An experimental study of the fluid-structure interaction of a cantilever panel with reflected shock impingement

Abstract: This paper presents an experimental investigation into the fluid-structure interaction of cantilever panels subjected to Mach 2 flow with reflected shock impingement. The study examines aluminum panels of varying thicknesses (3 mm, 2 mm, and 1 mm) mounted in a supersonic blowdown tunnel. A multitude of instrumentation was employed to capture the panel dynamics during the facility's transient startup and steady-state phases. A notable observation was the bending-torsional coupling of the 1 mm panel, which exhibited significant stiffening and sustained torsional oscillations throughout the run. Analysis of the pressure trace data revealed that the freestream pressure frequencies, while persistent, did not couple into the panel dynamics. The observed weak pressure waves, attributed to surface texture, and the possible three-dimensionality in the re-impinging shocks suggest complex flowfield-panel interactions that warrant further investigation. The findings highlight the multi-modal behavior of thin panels in supersonic flow, emphasizing the need for three-dimensional modeling to accurately capture the observed phenomena. Future work will focus on exploring the origin of the freestream pressure frequencies and the potential coupling of three-dimensional flowfield effects into the panel dynamics. Keywords: Fluid-structure interaction, FSI, Supersonic, Experimental, Structural dynamics